The present invention is directed toward a product accumulator and, more particularly, toward a flow-thru type wherein products are placed on a conveyer at one end and are discharged at the other end thereof but which allows the products to accumulate in the event of a backup at the discharge end.
Product accumulators of the general class to which the present invention pertains are not new, per se. They generally include a horizontally disposed conveyer belt having an infeed end onto which products such as glass vials, cans or bottles or the like are placed. Along the side of the main conveyer belt and running parallel therewith is a discharge conveyer belt. As the products are moved along the main conveyer belt, they eventually engage a guide rail or guide belt which is arranged at an angle across the main conveyer belt so as to guide the articles onto the discharge belt. Additional guide rails or the like in the vicinity of the end of the main conveyer adjacent the discharge conveyer ensure that the articles exit the discharge conveyer in a single row. In the event of a blockage at the discharge conveyer, the articles merely back up on the main conveyer belt as the belt slides under them.
Numerous examples of the foregoing can be seen in the prior art. General arrangements of these types can be seen in U.S. Pat. Nos. 1,990,549; 2,560,995; 2,763,359 and 3,162,291. Published Japanese application No. 55-161,715 also shows a similar arrangement.
Although the prior art accumulators function reasonably well, they all suffer from a similar problem. That is, there is no assurance that the first articles placed on the main conveyer will be part of the first group of articles to be discharged. In experimenting with accumulating conveyers of the general type described above, it has been found that once the articles begin to accumulate, articles which were first placed on the conveyer can be forced onto the side of the pack or recycled around the main conveyer without ever being discharged therefrom. Of course, the articles will eventually all be discharged once the infeed is stopped but this may occur only at the end of the day. Thus, articles placed on the conveyer in the morning may still be there at the end of the day which may be detrimental if the product within the vial or other container should have been processed within a certain amount of time. To Applicant's knowledge no accumulator conveyer of this type has addressed the problem of attempting to ensure that articles are discharged from the accumulator in an order which reasonably resembles the order in which the articles are fed thereto.